Chromium is an essential trace element for mammals. Its role in glucose metabolism has been investigated since the discovery in the 1950's of an organic chromium-associated compound, which was given the name glucose tolerance factor (GTF). GTF was derived from brewer's yeast and appeared to have insulin-potentiating activity. However, the chemical structure of GTF has been subject to debate.
A low molecular weight chromium-containing substance with insulin-potentiating activity, termed chromodulin, has also been reported. Chromodulin, which has been isolated from rabbit liver, porcine kidney, bovine colostrum and bovine liver, has been described as an oligopeptide consisting of glutamate, aspartate, glycine and cysteine residues bound to four chromic ions. However, U.S. Pat. No. 6,444,231 to Vincent tested a mixture comprising a 4:2:4:2:2 ratio of chromium, aspartate, glutamate, glycine, and cysteine, and found that this compound did not exhibit the GTF activity seen with chromodulin.
Several clinical studies indicate that chromium supplementation may improve diabetes control. Because of insufficient information on the use of chromium to treat diabetes, however, the U.S. National Institutes of Health has issued no recommendations for dietary chromium supplementation.